/// <summary>
/// Creates a file backed memory stream.
/// </summary>
/// <param name="stream">The <see cref="CustomFileStream"/> to buffer</param>
/// <param name="pool">The <see cref="MemoryPool"/> to allocate memory from</param>
/// <param name="header">The <see cref="FileHeaderBlock"/> to be managed when modifications occur</param>
/// <param name="isNewFile">Tells if this is a newly created file. This will make sure that the
/// first 10 pages have the header data copied to it.</param>
public BufferedFile(CustomFileStream stream, MemoryPool pool, FileHeaderBlock header, bool isNewFile)
{
m_fileStructureBlockSize = header.BlockSize;
m_diskBlockSize = pool.PageSize;
m_lengthOfHeader = header.BlockSize * header.HeaderBlockCount;
m_writeBuffer = new MemoryPoolStreamCore(pool);
m_pool = pool;
m_queue = stream;
m_syncRoot = new object();
m_pageReplacementAlgorithm = new PageReplacementAlgorithm(pool);
pool.RequestCollection += m_pool_RequestCollection;
if (isNewFile)
{
try
{
m_queue.Open();
byte[] headerBytes = header.GetBytes();
for (int x = 0; x < header.HeaderBlockCount; x++)
{
m_queue.WriteRaw(0, headerBytes, headerBytes.Length);
}
}
finally
{
m_queue.Close();
}
}
m_lengthOfCommittedData = (header.LastAllocatedBlock + 1) * header.BlockSize;
m_writeBuffer.ConfigureAlignment(m_lengthOfCommittedData, pool.PageSize);
}
public static DiskIo OpenFile(string fileName, MemoryPool pool, bool isReadOnly)
{
CustomFileStream fileStream = CustomFileStream.OpenFile(fileName, pool.PageSize, out int fileStructureBlockSize, isReadOnly, true);
DiskMedium disk = DiskMedium.OpenFile(fileStream, pool, fileStructureBlockSize);
return(new DiskIo(disk, isReadOnly));
}
/// <summary>
/// Creates a <see cref="DiskMedium"/> from a <see cref="stream"/>.
/// This will initialize the <see cref="stream"/> as an empty file structure.
/// </summary>
/// <param name="stream">An open <see cref="FileStream"/> to use. The <see cref="DiskMedium"/>
/// will assume ownership of this <see cref="FileStream"/>.</param>
/// <param name="pool">the <see cref="MemoryPool"/> to allocate data from</param>
/// <param name="fileStructureBlockSize">the block size of the file structure. Usually 4kb.</param>
/// <param name="flags">Flags to write to the file</param>
/// <returns></returns>
/// <remarks>
/// This will not check if the file is truely a new file. If calling this with an existing
/// archive file, it will overwrite the table of contents, corrupting the file.
/// </remarks>
public static DiskMedium CreateFile(CustomFileStream stream, MemoryPool pool, int fileStructureBlockSize, params Guid[] flags)
{
FileHeaderBlock header = FileHeaderBlock.CreateNew(fileStructureBlockSize, flags);
BufferedFile disk = new BufferedFile(stream, pool, header, isNewFile: true);
return(new DiskMedium(disk, header));
}
public static DiskIo CreateFile(string fileName, MemoryPool pool, int fileStructureBlockSize, params Guid[] flags)
{
//Exclusive opening to prevent duplicate opening.
CustomFileStream fileStream = CustomFileStream.CreateFile(fileName, pool.PageSize, fileStructureBlockSize);
DiskMedium disk = DiskMedium.CreateFile(fileStream, pool, fileStructureBlockSize, flags);
return(new DiskIo(disk, false));
}
/// <summary>
/// Creates a <see cref="DiskMedium"/> from a <see cref="stream"/>.
/// This will read the existing header from the <see cref="stream"/>.
/// </summary>
/// <param name="stream">An open <see cref="FileStream"/> to use. The <see cref="DiskMedium"/>
/// will assume ownership of this <see cref="FileStream"/>.</param>
/// <param name="pool">The <see cref="MemoryPool"/> to allocate data from.</param>
/// <param name="fileStructureBlockSize">the block size of the file structure. Usually 4kb.</param>
/// <returns></returns>
public static DiskMedium OpenFile(CustomFileStream stream, MemoryPool pool, int fileStructureBlockSize)
{
byte[] buffer = new byte[fileStructureBlockSize];
stream.ReadRaw(0, buffer, fileStructureBlockSize);
FileHeaderBlock header = FileHeaderBlock.Open(buffer);
BufferedFile disk = new BufferedFile(stream, pool, header, isNewFile: false);
return(new DiskMedium(disk, header));
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
/// <filterpriority>2</filterpriority>
public void Dispose()
{
if (!m_disposed)
{
try
{
m_disposed = true;
//Unregistering from this event gaurentees that a collection will no longer
//be called since this class utilizes custom code to garentee this.
m_pool.RequestCollection -= m_pool_RequestCollection;
lock (m_syncRoot)
{
if (m_pageReplacementAlgorithm != null)
{
m_pageReplacementAlgorithm.Dispose();
}
if (m_queue != null)
{
m_queue.Dispose();
}
if (m_writeBuffer != null)
{
m_writeBuffer.Dispose();
}
}
}
finally
{
m_queue = null;
m_disposed = true;
m_pageReplacementAlgorithm = null;
m_writeBuffer = null;
m_queue = null;
GC.SuppressFinalize(this);
}
}
}
/// <summary>
/// Creates a <see cref="DiskMedium"/> from a <see cref="stream"/>.
/// This will read the existing header from the <see cref="stream"/>.
/// </summary>
/// <param name="stream">An open <see cref="FileStream"/> to use. The <see cref="DiskMedium"/>
/// will assume ownership of this <see cref="FileStream"/>.</param>
/// <param name="pool">The <see cref="MemoryPool"/> to allocate data from.</param>
/// <param name="fileStructureBlockSize">the block size of the file structure. Usually 4kb.</param>
/// <returns></returns>
public static DiskMedium OpenFile(CustomFileStream stream, MemoryPool pool, int fileStructureBlockSize)
{
byte[] buffer = new byte[fileStructureBlockSize];
stream.ReadRaw(0, buffer, fileStructureBlockSize);
FileHeaderBlock header = FileHeaderBlock.Open(buffer);
BufferedFile disk = new BufferedFile(stream, pool, header, isNewFile: false);
return new DiskMedium(disk, header);
}
/// <summary>
/// Creates a <see cref="DiskMedium"/> from a <see cref="stream"/>.
/// This will initialize the <see cref="stream"/> as an empty file structure.
/// </summary>
/// <param name="stream">An open <see cref="FileStream"/> to use. The <see cref="DiskMedium"/>
/// will assume ownership of this <see cref="FileStream"/>.</param>
/// <param name="pool">the <see cref="MemoryPool"/> to allocate data from</param>
/// <param name="fileStructureBlockSize">the block size of the file structure. Usually 4kb.</param>
/// <param name="flags">Flags to write to the file</param>
/// <returns></returns>
/// <remarks>
/// This will not check if the file is truely a new file. If calling this with an existing
/// archive file, it will overwrite the table of contents, corrupting the file.
/// </remarks>
public static DiskMedium CreateFile(CustomFileStream stream, MemoryPool pool, int fileStructureBlockSize, params Guid[] flags)
{
FileHeaderBlock header = FileHeaderBlock.CreateNew(fileStructureBlockSize, flags);
BufferedFile disk = new BufferedFile(stream, pool, header, isNewFile: true);
return new DiskMedium(disk, header);
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
/// <filterpriority>2</filterpriority>
public void Dispose()
{
if (!m_disposed)
{
try
{
m_disposed = true;
//Unregistering from this event gaurentees that a collection will no longer
//be called since this class utilizes custom code to garentee this.
m_pool.RequestCollection -= m_pool_RequestCollection;
lock (m_syncRoot)
{
if (m_pageReplacementAlgorithm != null)
m_pageReplacementAlgorithm.Dispose();
if (m_queue != null)
m_queue.Dispose();
if (m_writeBuffer != null)
m_writeBuffer.Dispose();
}
}
finally
{
m_queue = null;
m_disposed = true;
m_pageReplacementAlgorithm = null;
m_writeBuffer = null;
m_queue = null;
GC.SuppressFinalize(this);
}
}
}
/// <summary>
/// Creates a file backed memory stream.
/// </summary>
/// <param name="stream">The <see cref="CustomFileStream"/> to buffer</param>
/// <param name="pool">The <see cref="MemoryPool"/> to allocate memory from</param>
/// <param name="header">The <see cref="FileHeaderBlock"/> to be managed when modifications occur</param>
/// <param name="isNewFile">Tells if this is a newly created file. This will make sure that the
/// first 10 pages have the header data copied to it.</param>
public BufferedFile(CustomFileStream stream, MemoryPool pool, FileHeaderBlock header, bool isNewFile)
{
m_fileStructureBlockSize = header.BlockSize;
m_diskBlockSize = pool.PageSize;
m_lengthOfHeader = header.BlockSize * header.HeaderBlockCount;
m_writeBuffer = new MemoryPoolStreamCore(pool);
m_pool = pool;
m_queue = stream;
m_syncRoot = new object();
m_pageReplacementAlgorithm = new PageReplacementAlgorithm(pool);
pool.RequestCollection += m_pool_RequestCollection;
if (isNewFile)
{
byte[] headerBytes = header.GetBytes();
for (int x = 0; x < header.HeaderBlockCount; x++)
{
m_queue.WriteRaw(0, headerBytes, headerBytes.Length);
}
}
m_lengthOfCommittedData = (header.LastAllocatedBlock + 1) * (long)header.BlockSize;
m_writeBuffer.ConfigureAlignment(m_lengthOfCommittedData, pool.PageSize);
}
